Parthner Steel Dutch Ovens are Hard-Anodized Aluminum to prevent Aluminum getting into the food. Season the Oven before use to provide a non-stick surface. The sides and bottom are flat for maximum size and easy clean-out. There are 5 standard sizes: 10" (5 qt), 11" (8 qt), 12" (10 qt), 13" (12 qt), 14" (14 qt). All ovens nest perfectly, and if not being used on an oven, the lid can double as a griddle.